JP4539915B2 - Hydraulic oil tank structure - Google Patents

Description

  The present invention relates to a hydraulic oil tank structure.

  As shown in FIG. 7, a construction machine such as a wheel loader includes a vehicle body 51 and a work machine 52 protruding from the vehicle body 51. The work implement 52 has a boom 53 protruding forward from the vehicle body 51 and a bucket 54 attached to the tip of the boom 53, and the vehicle body 51 and the boom 53 are connected via a boom cylinder 55. Has been. Further, the boom 53 and the bucket 54 are connected by a bucket cylinder 57 via a link 56. Therefore, the boom 53 swings around the pivot 58 on the vehicle body 51 side by the expansion and contraction of the boom cylinder 55, and the bucket 54 centers around the pivot 59 by the expansion and contraction of the bucket cylinder 57. Swing.

  By the way, the boom cylinder 55 and the bucket cylinder 57 are hydraulic devices. For this reason, in such a construction machine, a hydraulic oil tank or the like is mounted on the vehicle body 51, and each hydraulic device is operated by supplying the hydraulic oil in the hydraulic oil tank to each hydraulic device. In this case, in the hydraulic oil tank, when the hydraulic oil is supplied to the hydraulic equipment, the hydraulic oil level in the tank moves up and down to cause a pressure fluctuation in the tank. Therefore, an air chamber is provided so that the internal pressure change due to the liquid level fluctuation can be alleviated. Usually, about half of the upper part of the hydraulic oil tank is used as the air chamber.

  Moreover, it may be necessary to arrange | position a tank oil level on the upper level with respect to a pump from the relationship of the suction performance of the pump for supplying the hydraulic oil of a hydraulic oil tank to each hydraulic equipment. However, in consideration of maintainability, it is preferable to arrange the tank at a position as low as possible of the vehicle body 51. For this reason, as shown in FIG. 8, the hydraulic oil tank 60 and the air chamber 61 are separated as a hydraulic oil tank and the oil chamber 60 and the air chamber 61 are connected by a connecting pipe 62. It is also possible to increase the oil level while disposing the main body 51 at a low position. In this case, when the hydraulic oil in the oil chamber 60 returns with the vehicle body 51 tilted, the air in the upper portion of the oil chamber is confined, and the hydraulic oil is ejected into the air chamber 61 like a water gun. There is a problem. Further, even when almost all of the hydraulic oil from the hydraulic equipment returns to the hydraulic oil tank and the vehicle body 51 tilts with the hydraulic oil in the hydraulic oil tank to the upper limit, the hydraulic oil does not flow into the air chamber 61. It is necessary to define the relative height of the oil chamber 60 and the air chamber 61 or to devise the handling of the connecting pipe 62.

In addition, there is one described in Patent Document 1 that prevents hydraulic oil from flowing into the air chamber 61 even when the vehicle body 51 is inclined. In the thing of this patent document 1, as shown in FIG. 9 and FIG. 10, after letting out the connecting pipe 62 ahead from the upper part of the center part of the oil chamber 60, it is taken out to the side and the outer periphery of the oil chamber 60 is shown. And then extending toward the center of the vehicle body 51, and then moving backward along the vehicle body 51 to bend upward at the top of the air chamber 61 to form the protrusion 64. Then, it is bent downward and connected from the rear of the air chamber 61 to the lower portion of the air chamber.
Japanese Patent No. 2922882

  For this reason, in the thing of patent document 1, it becomes long and complicated as the connecting pipe 62, it is inferior to assemblability, and the freedom degree on a layout is also low. Although the connection pipe 62 is elongated to some extent, the air above the oil chamber 60 is trapped when the hydraulic oil returns to the oil chamber 60 with the vehicle body 51 tilted. There is still a risk that hydraulic oil will be ejected into the air chamber 61 like a water gun.

  The present invention has been made to solve the above-described conventional drawbacks, and its purpose is to freely set the arrangement of the oil chamber and the air chamber and to prevent the inflow of hydraulic oil into the air chamber. Another object of the present invention is to provide a hydraulic oil tank structure that can be connected and does not complicate the connection of the connecting pipe.

  Therefore, the hydraulic oil tank structure according to claim 1 includes an oil chamber, an air chamber, and a separation chamber disposed above the oil chamber, and the opening of the connecting pipe from the oil chamber is arranged on the lower side of the separation chamber. And the opening of the connecting pipe from the air chamber is provided on the upper side of the separation chamber, and the oil chamber and the air chamber are connected via the separation chamber.

  The hydraulic oil tank structure according to claim 2 is characterized in that the oil chamber and the air chamber are provided side by side so that the upper portion of the oil chamber covers the air chamber.

  According to the hydraulic oil tank structure of the first aspect, it is possible to simplify the connection of the connecting pipe. Further, even if the hydraulic oil temporarily flows into the separation chamber due to the inclination of the vehicle body, the hydraulic oil returns to the oil chamber through the connecting pipe due to gravity and does not flow into the air chamber. Can be freely set.

  According to the hydraulic oil tank structure of the second aspect, even when almost all of the hydraulic oil from the hydraulic equipment returns to the hydraulic oil tank, and the hydraulic oil is in the hydraulic oil tank up to the upper limit, the cross-sectional area of the upper part of the oil chamber is Because it is large, it can secure a larger capacity air layer, so even if the vehicle body tilts, it becomes difficult for hydraulic oil to flow into the separation chamber, and it is possible to more reliably prevent hydraulic oil from flowing into the air chamber. .

  A specific embodiment of the hydraulic oil tank structure of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a simplified configuration diagram of the hydraulic oil tank structure. The hydraulic oil tank structure includes an oil chamber 1 and an air chamber 2, and the oil chamber 1 and the air chamber 2 are connected via a separation chamber 3. The separation chamber 3 is disposed higher than the oil chamber 1, the oil chamber 1 and the separation chamber 3 are connected via a connecting pipe 4, and the air chamber 2 and the separation chamber 3 are connected via a connecting pipe 5. . One end of the connecting pipe 4 opens to the uppermost side of the oil chamber 1, and the other end opens to the lowermost side of the separation chamber 3. One end of the connecting pipe 5 opens to the upper side of the separation chamber 3, and the other end opens to the upper side of the air chamber 2. In this embodiment, the opening of the connecting pipe 5 to the air chamber 2 is on the upper side, but it is not necessarily on the upper side. In this embodiment, the capacity of the oil chamber 1 is about 140 liters, the capacity of the air chamber 2 is about 40 liters, and the capacity of the separation chamber 3 is about 5 liters. The upper limit of the hydraulic oil O stored in the oil chamber 1 is about 130 liters. Therefore, when the hydraulic oil O is put to the upper limit, the oil chamber 1 is set to have an air layer 6 of about 10 liters.

  The oil chamber 1 is a box and is mounted on a vehicle body 51 of a construction machine such as a wheel loader as shown in FIG. As shown in FIG. 6, a first partition chamber 13 including a cylindrical body 17 and a bottom wall 16 is provided on the upper side in the oil chamber 1, and a cylindrical filter 18 is housed in the first partition chamber 13. Yes. A return pipe 43 is connected to the cylindrical body 17 of the first partition chamber 13, and the hydraulic oil O returned from the hydraulic device flows into the first partition chamber 13. A first through hole 22 is provided in the upper wall 20 of the oil chamber 1, and the cylindrical filter 18 can be detached from the oil chamber 1 through the first through hole 22. A lid member 24 is fixed with a bolt above the first through hole 22 of the oil chamber 1, and the tubular filter 18 is pressed against the bottom wall 16 of the first partition chamber 13 by the lid member 24 via the spring member 23. An air vent plug 25 is screwed into the lid member 24.

  A cylindrical body 27 is provided on the bottom wall 16 of the partition chamber 13, and a lower portion of the cylindrical body 27 is inserted into a receiving portion 14 that is provided on the bottom wall 26 of the oil chamber 1 and is open at the top. In the figure, reference numeral 10 denotes a rib for reinforcing the oil chamber 1. A side wall of the floating portion 14 is provided with a second partition chamber 15 including an upper wall 29a having an opening and a cylindrical body 29, and a strainer 28 is attached to the opening position of the upper wall 29a. A strainer rod 30 extends from the strainer 28. A second through hole 31 is provided in the upper wall 20 of the oil chamber 1, and a lid member 32 is fixed above the second through hole 31 with a bolt. The tip of the strainer rod 30 is connected to the lid member 32 via an elastic member 33. The strainer 28 is pressed against the upper wall 29 a of the second partition chamber 15 by the lid member 32 through the elastic member 33. Further, the strainer 28 can be detached from the oil chamber 1 through the second through hole 31 by removing the lid member 32. An outgoing pipe 44 is connected to the second compartment 15.

  With the above configuration, the hydraulic oil O returned from the hydraulic equipment first flows into the first partition chamber 13, is filtered by the cylindrical filter and flows into the lower receiving portion 14, and the cylindrical body 27 and the receiving portion 14 are moved. pass. By passing upward through the cylindrical body 27 and the receiving portion 14, air bubbles contained in the returned hydraulic oil O are prevented from flowing directly into the second partition chamber 15. By driving a hydraulic pump (not shown), the hydraulic oil O in the oil chamber 1 is further filtered by the strainer 28, flows into the second partition chamber 15, and flows out to the outgoing pipe 44.

  As shown in FIGS. 2 to 5, the oil chamber 1 and the air chamber 2 are provided side by side so that the upper portion of the oil chamber 1 covers the air chamber 2. A recess 36 is provided in the portion (rear wall), and the air chamber 2 formed of a flat box is formed in the recess 36. The thickness dimension of the air chamber 2 is set so that the rear end wall portion 37 of the upper portion of the oil chamber 1 and the rear end wall 38 of the air chamber 2 substantially coincide with each other.

  The separation chamber 3 needs to be arranged higher than the oil chamber 1. In this example, the separation chamber 3 is disposed above the oil chamber 1, and the separation chamber 3 is configured at the protruding portion 40 of the vehicle body 51 above the oil chamber 1 as shown in FIGS. 4 and 5. The box is fixed. The connecting chamber 4 connects the oil chamber 1 and the separation chamber 3, and the connecting tube 5 connects the air chamber 2 and the separation chamber 3. The connecting pipe 4 is attached to the upper wall 20 of the oil chamber 1 and opens to the upper side of the oil chamber 1, and the connecting pipe 5 is attached to the upper part of one side wall 42 of the air chamber 2 to be higher than the air chamber 2. Open to the side. The connecting pipe 4 and the connecting pipe 5 are both attached to the bottom wall 41 of the separation chamber 3, but the connecting pipe 4, which is the side connected to the oil chamber 1, opens on the lower side of the separation chamber 3, and the air chamber The connecting pipe 5, which is connected to 2, opens at the upper side of the separation chamber 3.

  According to the hydraulic oil tank structure, since the oil chamber and the air chamber are connected via the separation chamber disposed higher than the oil chamber, the surrounding of the connecting pipe can be simplified. Even if the hydraulic oil temporarily flows into the separation chamber due to tilting or rising of the oil level, the hydraulic oil returns to the oil chamber through the connecting pipe due to its weight and does not flow into the air chamber. The relative height of can be set freely.

  In the above embodiment, since the oil chamber and the air chamber are provided side by side so that the upper portion of the oil chamber covers the air chamber, most of the hydraulic oil from the hydraulic equipment returns to the hydraulic oil tank, Even in a state in which the hydraulic oil reaches the upper limit in the tank, a large capacity air layer can be secured in the oil chamber. For this reason, even if the vehicle body is tilted, it is difficult for the hydraulic oil to flow into the separation chamber, and the hydraulic oil can be reliably prevented from flowing into the air chamber. Note that the oil chamber and the air chamber may be arranged separately from each other without providing the air chamber in the oil chamber, and the degree of freedom in layout is great.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, the capacities of the oil chamber 1, the air chamber 2, and the separation chamber 3 can be arbitrarily set, and can be changed according to the amount of hydraulic oil O to be used. In addition, the air chamber 2 may be higher than the oil level of the oil chamber 1 as the arrangement position of the air chamber 2 with respect to the oil chamber 1. Further, as shown in FIG. 2 and the like, when the oil chamber 1 and the air chamber 2 are provided (adjacent), in the above embodiment, a recess 36 is provided in a part of the wall of the oil chamber 1, Although the air chamber 2 is fitted, the air chamber 2 may be disposed in contact with or close to the oil chamber 1 without providing such a recess 36. The use of the hydraulic oil tank structure is not limited to the wheel loader, and various construction machines are targeted.

It is a simplified diagram showing an embodiment of a hydraulic oil tank structure of the present invention. It is a principal part perspective view of the said hydraulic oil tank structure. It is a side view of the said hydraulic oil tank structure. It is a side view which shows the relationship between the oil chamber of the said hydraulic oil tank structure, an air chamber, and a separation chamber. It is a front view which shows the relationship between the oil chamber of the said hydraulic oil tank structure, an air chamber, and a separation chamber. It is an expanded sectional view of the oil chamber of the hydraulic oil tank structure. It is a simplified diagram of a wheel loader. It is a simplified diagram showing the arrangement relationship between an oil chamber and an air chamber of a conventional hydraulic oil tank structure. It is a top view which shows arrangement | positioning of the conventional hydraulic oil tank structure. It is a rear view which shows arrangement | positioning of the conventional hydraulic oil tank structure.

Explanation of symbols

  1 .... oil chamber, 2 .... air chamber, 3 .... separation chamber, 4, 5 .... connecting pipe

Claims (2)

  An oil chamber, an air chamber, and a separation chamber disposed above the oil chamber, the opening of the connection pipe from the oil chamber is provided on the lower side of the separation chamber, and the opening of the connection pipe from the air chamber Is provided on the upper side of the separation chamber, and the oil chamber and the air chamber are connected via the separation chamber.   2. The hydraulic oil tank structure according to claim 1, wherein the oil chamber and the air chamber are provided side by side so that an upper portion of the oil chamber covers the air chamber.